The decision, by a 5-to-4 vote that divided along ideological lines, probably means the Supreme Court will never rule on the constitutionality of that 2008 law.

More broadly, the ruling illustrated how hard it is to mount court challenges to a wide array of antiterrorism measures, including renditions of terrorism suspects to foreign countries and targeted killings using drones, in light of the combination of government secrecy and judicial doctrines limiting access to the courts.